1. Field of the Invention
The present invention relates to a return jet fitting, and more particularly, for such a fitting as provides a more efficient circulation of return water in swimming pools and spas. More specifically, the present invention relates to an eyeball fitting that may be modified on site to obtain a desired water circulation pattern.
2. Description of the Prior Art
Pools and spas require additional cleaning beyond what occurs as a result of in-line filtration of the water as it circulates. In addition to using skimmers to remove floating debris, traditionally suction has been used to remove dirt, leaves, and the like from the shell (inner walls, coves, steps and floor). One of the earliest tools applied suction through a cleaning head attached to a long pole. A flexible hose connected the cleaning head to the skimmer, drawing in water and debris through the head for discharge into the general pool filtration system.
Manual cleaners require both the time and effort of the pool/spa owner or the hiring of a pool man. One solution has been the development of several types of xe2x80x9cautomatic cleaners.xe2x80x9d These are typically connected to a pressurized source of water that both powers its movement and creates the suction for cleaning. Early versions required water of higher pressure than is normally provided by the general circulation pumps; however, present devices, such as those offered under the KREEPY KRAULY(copyright) brand, are more efficient and do not require a separate source of high-pressure water.
Although no additional booster pumps are required by the more modern automatic cleaning systems, their cleaning operation continues only during operation of the general circulation pumps. The long hours of pump operation required to achieve a reasonable level of cleaning represent a significant energy cost for all but the smallest of pools.
An alternate technique relies upon a system of specialized return line fittings and active drains. The fittings direct currents of water to flow the debris towards active drain locations. These drains open during a cleaning mode, permitting the removal of water and entrained debris that had been directed to the general area by the generated water currents. Timed valves and other control mechanisms coordinate fitting flow and drain openings to maximize system efficiency. Many of these systems also require additional pumps and circulation systems to operate effectively.
This complexity comes at a price of increased installation and maintenance costs. Additionally, it is economically not possible to retrofit these systems into existing pools. Other cleaning systems have evolved intending to make use of the general circulation system in a manner similar to the more complex flow and drain systems.
In most systems, the general water circulation begins with removal of pool or spa water from a bottom main drain. Water flows to the pump and after filtration and heating (when required); the water is returned through xc2xe-3 inches piping to the pool or spa. Where the pool is of gunite, fiberglass or vinyl construction, a return loop line is provided about the perimeter of the pool. Tees are provided along the loop line to connect a pipe that extends through the pool wall these pipes are identified as the xe2x80x9creturn lines,xe2x80x9d and enter the pool approximately 9-14 inches below the intended water line. An average-sized pool will have 4-6 of such return lines.
The conventional return heads, known as xe2x80x9ceyeball fittings,xe2x80x9d provide an outflow stream that circulates only the top 1-18 inches of water in a 6 foot deep pool. The main drain draws water from only 1 foot away, leaving a 4-5 foot (vertical) area of water that is xe2x80x9cdeadxe2x80x9d in terms of circulation. As a result, chemical and thermal conditioning of the pool water require more time to accomplish, which means longer operation of the electric pump.
The teachings of Johnson, U.S. Pat. No. 4,520,514, suggest a very specialized return fitting that includes a bottom slot for directing a stream of water downward, along the pool wall. Some of the more generally available eyeball fittings include modifications such as a xe2x80x9cslotted eyeballxe2x80x9d and a xe2x80x9cpulsator eyeballxe2x80x9d each intended to provide variations on the straight-ahead stream of water and the resultant dead (circulation) areas.
Elimination of this dead area of poor water circulation requires a concerted effort in terms of return water flow and direction. The specialized return line fittings and active drains achieves greater mixing but at a cost of greatly increased complexity and expense. A need exists to obtain better pool circulation that makes use of an existing water circulation system, and in a manner that permits retrofitting to existing pools and spas.
It is an object of the present invention to provide a replacement eyeball fitting for pool and spa return lines that enables greatly increased circulation efficiency within pools and spas, permitting more effective cleaning of interior pool surfaces (including benches, floors, coves, and steps) during the operation thereof.
In this regard, an eyeball fitting has been modified to permit jetting up to 80% of the water volume down to the pool floor, through the dead water zone. A plurality of potential jet openings are molded into the eyeball fitting, permitting their selective removal on site, based upon the direction of water flow required at a specific return fixture location.
Using the jet openings appropriate for a particular location results in an uncompromised surface circulation, yet provides a turn rate to the overall pool or spa water volume that enables pool heating in 70% of the time previously required. Additionally, when used with a roving suction cleaning device, this improved circulation permits full cleaning in 2-3 hours, instead of the 8-12 hours previously required. Such improved circulation also results in less treatment chemicals required to saturate the total water volume.
While normal circulation of water in a 12,000 gallon pool might require 7 to 8 hours before a satisfactory treatment chemical level is achieved, the controlled direction of water possible with the modified eyeball fittings permits full circulation in approximately 3 xc2xd hours. Additional dead circulation zones formed by pool shape and circulation patterns can also be addressed with the present, modified eyeball fitting. For example, pools with curved surfaces can form dead zones cut off from the general surface circulation. It is possible to remove selective other of the potential fitting openings to permit water to be jetted to both the right and left, simultaneously with the directing of water downward, to clean steps, benches, walls, coves, and floor, as previously discussed.